Nano-optics is the study of optical interactions with matter on a subwavelength scale. Nano-optics has numerous applications in optical technologies such as nanolithography, optical data storage, photochemistry on a nanometer scale, solar cells, materials imaging and surface modification with subwavelength lateral resolution, local linear and nonlinear spectroscopy of biological and solid-state structures, quantum computing, quantum communication and optical networking.
Nanolithography is a method for the creation of nanoscale structures. Usually one creates a pattern of a desired nanostructure in a template material, and then uses this template to fabricate the nanostructure. Nanolithography can employ a computer controlled electron beam and an electron sensitive template material. Several other nanolithography techniques employ nanotools, like the scanning probe microscope (SPM) or atomic force microscope (ATM) to create the templates. However, these techniques are extremely expensive and slow.
One common method of nanolithography, used particularly in the creation of microchips, is known as photolithography. Photolithography is limited in the size it may reduce to, however, because if the wavelength of light used is made too small the optical lens simply absorbs the light in its entirety. Photolithography is limited due to light diffraction limitations, i.e. the nanostructure dimensions are smaller than the wavelength of the light. Currently, photolithography can create features around the 90 nm scale. This means that photolithography cannot reach the super-fine sizes of some alternate technologies, such as electron-beam lithography. Using an electron beam to draw a pattern nanometer by nanometer, incredibly small sizes (on the order of 20 nm) may be achieved. Industrial applications of electron-beam lithography have been limited because it is more expensive and time consuming than photolithography. Recent nanolithography technologies, such as extreme ultraviolet lithography, are capable of using light at wavelengths of about 13.5 nm. While hurdles still exist in this new field, nanolithography promises the possibility of sizes far below those produced by current industry standards. Other nanolithography techniques include dip-pen nanolithography, in which a small tip is used to deposit molecules on a surface. Dip-pen nanolithography can achieve very small sizes, but cannot currently go below 40 nm.
Prior art nanolithography techniques for generating structures on various surfaces are described in U.S. Pat. No. 6,569,575 entitled “Optical lithography beyond conventional resolution limits;” U.S. Pat. No. 6,833,162 entitled “Colored nanolithography on glass and plastic substrates;” U.S. Pat. No. 7,057,832 entitled “Microlens for projection lithography and method of preparation thereof;” and U.S. Patent Application Publication No. 20050221202 entitled “Wavelength filtering in nanolithography,” all of which are hereby incorporated by reference in their entireties for the teachings therein.
It would be beneficial to develop an inexpensive and effective solution for nanolithography that may both successfully and easily be used to create sub-micron structures.